Glacier Bay National Park

Visitors to Glacier Bay National Park in Alaska have the opportunity to witness a diverse landscape that includes glaciers, fjords, and freshwater rivers and lakes—even a lounging harbor seal or two.

Photograph by W.E. Garrett

Location: Alaska

Established: December 2, 1980

Size: 3,280,198 acres

When Capt. George Vancouver sailed the Alaska coast in 1794, Glacier Bay did not exist. It lay beneath a sheet of glacial ice several miles wide and thousands of feet thick. Since then, in one of the fastest glacial retreats on record, the ice has shrunk back 65 miles to unveil new land and a new bay, now returning to life after a long winter's sleep.

Scientists call Glacier Bay a living laboratory for the grand processes of glacial retreat, plant succession, and animal dynamics. It is an open book on the last ice age. At the southern end, where the ice departed 200 years ago, a spruce-hemlock rain forest has taken root. Farther north, the more recently deglaciated land becomes rugged and thinly vegetated.

The bay branches into two major arms, the west arm and Muir Inlet, which themselves branch into smaller inlets. There, on slopes deglaciated 50 to 100 years ago, alder and willow grow, while mosses, mountain avens, and dwarf fireweed pioneer areas exposed within 30 years.

The new vegetation creates habitats for wolves, moose, mountain goats, black bears, brown bears, ptarmigan, and other wildlife, and the sea supports a food chain that includes salmon, bald eagles, harbor seals, harbor porpoises, humpback whales, and killer whales—all in an environment less than 200 years old.

Glacier Bay is home to nine tidewater glaciers that calve. In part because of variations in snow accumulations, most glaciers in the eastern and southwestern areas of the bay are receding, while several on its west side are advancing.

The glaciers calve icebergs that hit the water with a sound like cannon shot. "White thunder," the Tlingit called it, the awesome voice of glacial ice. An iceberg's color often reveals its makeup; dense bergs are blue, while those filled with trapped air bubbles are white.

Did You Know?

Water originating in Glacier National Park—much of it from snowmelt—can be considered the headwater of the continent. Water that runs down Triple Divide Peak flows in three directions, eventually winding up in the Pacific Ocean, the Gulf of Mexico, and Hudson Bay.